Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F1/00—Wet end of machines for making continuous webs of paper
  • D21F1/44—Watermarking devices
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
  • B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
  • B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
  • B42D25/30—Identification or security features, e.g. for preventing forgery
  • B42D25/355—Security threads
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F1/00—Wet end of machines for making continuous webs of paper
  • D21F1/0027—Screen-cloths
  • D21F1/0036—Multi-layer screen-cloths
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
  • D21H21/14—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
  • D21H21/40—Agents facilitating proof of genuineness or preventing fraudulent alteration, e.g. for security paper
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
  • D21H21/14—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
  • D21H21/40—Agents facilitating proof of genuineness or preventing fraudulent alteration, e.g. for security paper
  • D21H21/42—Ribbons or strips
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
  • Y10T428/24273—Structurally defined web or sheet [e.g., overall dimension, etc.] including aperture
  • Y10T428/24322—Composite web or sheet
  • Y10T428/24331—Composite web or sheet including nonapertured component
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
  • Y10T428/24479—Structurally defined web or sheet [e.g., overall dimension, etc.] including variation in thickness
  • Y10T428/24612—Composite web or sheet
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T442/00—Fabric [woven, knitted, or nonwoven textile or cloth, etc.]
  • Y10T442/10—Scrim [e.g., open net or mesh, gauze, loose or open weave or knit, etc.]
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T442/00—Fabric [woven, knitted, or nonwoven textile or cloth, etc.]
  • Y10T442/30—Woven fabric [i.e., woven strand or strip material]
  • Y10T442/3472—Woven fabric including an additional woven fabric layer

Definitions

• the invention relates to a method for manufacturing a fibrous jet, in particular paper, used in particular for making security documents such as banknotes, checks, tickets, admission tickets to cultural events or sports . It also concerns the training canvas and the method of making the canvas.
• paper means any sheet obtained by wet process using a suspension of natural cellulose fibers and / or mineral or organic fibers other than cellulose, possibly synthetic, which may contain various fillers. and various additives commonly used in stationery.
• a watermark is used to authenticate a paper document.
• This watermark may be a "dark" watermark.
• Such a watermark is obtained during the manufacture of the fibrous sheet by means of round shapes comprising the engraved imprint of the watermark to be reproduced.
• a sheet with a watermark is then obtained which appears dark when the sheet is viewed in transmitted light, the dark areas being due to an accumulation of fibers, during the formation of the sheet in the recessed portions of the impression.
• the density of fibers and therefore the thickness of the sheet are greater in these areas than in the rest of the sheet.
• Such a watermark therefore has extra thicknesses. On average, for finished security sheets such as banknotes, these extra thicknesses measure 20 ⁇ m and can reach 35 ⁇ m for the darkest watermarks.
• Another widely used security feature is the security thread.
• the security thread is in the form of a continuous long strip incorporated in the fiber suspension during the manufacture of the sheet, or alternatively between two fibrous layers.
• the wire may be seen in openings (called
• the security threads and strips generally have a width of between 1 and
• a thickness of between 10 and 50 ⁇ m are positioned from one edge to another opposite edge, over a whole length, width or height of the sheet and thus do not occupy the entire surface of the sheet . As a result, they also create an extra thickness relative to the rest of the sheet.
• one skilled in the art can position shims between the sheets. He can also cross the piles of some sheets to alternate the extra thicknesses of the piles. This therefore requires handling of the sheets, necessary to allow proper processing of the sheets, but which leads to additional work and tedious hindering rapid processing of the sheets, particularly at the time of printing.
• sheets may be calendered with watermarks, which makes the watermarks brighter and undermines the securing of the sheet.
• watermarks makes the watermarks brighter and undermines the securing of the sheet.
• EP 0773220 discloses a fibrous security sheet comprising a watermark and at least one safety strip placed so as to compensate for their extra thickness, and so that the sheet has a better flatness.
• the object of the present invention is therefore to provide a method of manufacturing a fibrous jet comprising such security elements, the surface of which has no known thicknesses.
• the Applicant has found that this object is achieved by a process for manufacturing a fibrous jet by wet process on a forming web of a paper machine comprising a stack of webs, said stack of webs comprising a surface fabric and at least one a superimposed undercloth, said fibrous jet comprising at least one element of a given thickness, characterized in that it comprises the following step: forming said jet by draining an aqueous suspension based on fibers on said forming fabric whose stack of webs comprises a reduced drainage area compared to that of the first sub-fabric, at least one sub-fabric and / or under the surface fabric, said reduced dewatering region being in correspondence with the position that said element will have.
• a "forming fabric" of a paper machine is made of a stack of several woven cloths made of metal or plastic threads, allowing the suspension of fibers deposited there to form a jet to drain out.
• fibrous in particular to have a sufficiently rigid canvas to support the paper process.
• outer fabric refers to the outer web of the stack of webs, on which the fibrous suspension is dripped to form a fibrous jet, optionally embossed to create reliefs such as watermarks within said jet.
• under-canvas is meant any canvas of the stack of webs other than the surface fabric.
• first sub-canvas the under-canvas located directly under the surface cloth
• second sub-canvas the under-canvas located directly under the first sub-canvas.
• the linear density in yarns is homogeneous for a given canvas or sub-fabric and decreases from the surface fabric to the last under-fabric, knowing that the lower the density of yarns, the higher the dewatering speed. .
• the term "reduced drainage region" in relation to the first sub-fabric means a region in which the dewatering speed is slowed compared with that of the first sub-fabric.
• the underlay provided with at least one reduced dewatering zone is the first sub-fabric, directly positioned under the surface fabric.
• the amount of deposited fibers is less than the amount of fibers deposited on the remainder. of the superficial canvas.
• the fiber thickness will be less than in the rest of the fibrous jet, creating a depression.
• the thickness of the security element placed in the same place will then be offset by the decrease in the amount of deposited fibers.
• the fibrous jet will not have a noticeable thickness on its surface.
• An advantage of the process according to the invention is that it makes it possible to obtain a fibrous jet which does not have any known excess thickness on its surface without having to modify the surface fabric, which makes it possible in particular not to have to change the embossed surface fabrics. currently used, for example for the manufacture of watermarks.
• Another advantage of the method according to the invention is that it modifies only very little, if at all, the structure of the security element whose thickness is compensated. Part of the thickness of the element that generates an extra thickness is no longer on the surface of the fibrous jet, the element being "cashed" in the depression created in the jet.
• the reduced dewatering region has a dewatering rate equal to or less than that of the surface fabric.
• said element of a given thickness is formed or incorporated in the wet jet during the formation of said jet on said forming web.
• it may be a watermark or security thread.
• said element of a given thickness is attached to said jet after formation of said jet.
• it may be a flat foil element or a flat element of reduced size (patch), fixed to the the surface of the jet, the element being able to be fixed once the fibrous jet has dried, off the line of the paper machine.
• the fiber-based suspension comprises cellulosic fibers, in particular cotton fibers, and / or organic synthetic fibers and / or mineral fibers.
• the stack of webs is the roll forming fabric of a round shape of a paper machine.
• This embodiment is particularly advantageous when the security element which is compensated for the excess thickness is a watermark or an element such as a security thread appearing in a window.
• the stack of fabrics is the forming fabric of a flat table of a paper machine.
• the reduced dewatering region has dimensions equal to or substantially greater than those of the security element of a corresponding given thickness.
• the security element generating, if it is a watermark, a relief on the surface of this depression.
• the security element has a thickness less than that of the fibrous jet, and preferably between 10 microns and 60 microns, in particular between 20 and 40 microns.
• the fibrous jet has a thickness of between 80 and 120 ⁇ m.
• the fabric and the sub-fabrics consist of interlaced threads forming meshes.
• the region of the reduced drip underlayer has a son density equal to or greater than that of the surface fabric.
• the density of the reduced drainage region is 12 threads / cm (30 mesh), while the surface fabric density is 8 threads / cm (20 mesh), with constant wire diameter.
• the compensation of the thickness of said element on the surface of the sheet due to the presence of the reduced drainage region is such that the top of the highest section of the relief generated by the security element is located. at the same level than the rest of the surface of the vellum part of the fibrous jet.
• a fibrous jet having a flat surface on its entire, on each of its faces.
• the surface fabric comprises embossings, in particular hollow embossings, facing the reduced drainage region.
• the surface fabric is embossed for the creation of watermarks. It can also be provided with parts obstructing the dripping, galvano type, to create openings, crossing or not, in the fibrous jet.
• the first and / or second sub-fabric have an opening facing the embossed areas of the surface fabric.
• the first sub-fabric comprises an opening facing the position of said element of a given thickness, and a perforated piece of dimensions approximately equal to those of said opening and allowing reduced drainage by relative to said sub-fabric, is fixed under the surface fabric at a position corresponding to said element.
• the first sub-fabric comprises an opening facing the position of said element of a given thickness, and a perforated piece of dimensions approximately equal to those of said opening and allowing reduced drainage relative to said sub-fabric, is fixed in this opening to the first sub-fabric at a position corresponding to said element.
• said perforated piece of dimensions approximately equal to those of said opening is embossed identically to the embossings of said surface fabric.
• At least one reduced dewatering region is in a discrete form.
• This embodiment is particularly advantageous when the element whose thickness is compensated is a continuous band incorporated in the fibrous jet and partially flush in openings on the surface of said fibrous jet or when it is about watermarks, or of a flat element of dimensions reduced compared to the dimensions of the jet (patch).
• At least one underlayer comprises at least one reduced freeness region in the form of a continuous zone of given width extending throughout the entire length or width of the said formation cloth.
• This embodiment is particularly advantageous when the element whose thickness is compensated is a continuous band at least partially incorporated into the fibrous jet, such as a security thread appearing or not in windows.
• the method comprises a step in which said continuous strip is incorporated during the formation of the fibrous jet on the forming web, in the zone facing the reduced drainage region.
• the strip introduced is a strip or a security thread and has a width of between 1 and 30 mm, in particular between 1 and 10 mm.
• the fibrous jet comprises a dark or shaded watermark, said watermark being formed by embossings comprising embossed portions recessed in the surface fabric, said embossments being opposite reduced drainage regions .
• said reduced dewatering region comprises several zones having different dewatering rates.
• said reduced drainage region comprises a central zone surrounded by at least two edge zones, said central zone and edge zones having different dewatering speeds.
• the central zone has a lower dewatering speed than the dripping speeds of the edge zones.
• the present invention also relates to a web for forming a paper machine comprising a stack of webs comprising a surface fabric and at least one underlayer, used during the formation of a fibrous jet, which is characterized by the fact that at least one dewatering region reduced compared to the first underlayer is located at the level of at least one undercloth and / or fixed under the surface fabric.
• the dewatering region has a reduced dewatering rate equal to or less than the dewatering speed of the surface fabric.
• the first sub-fabric comprises a reduced drainage region.
• all the reduced drainage regions are on the first underlay.
• the surface fabric comprises embossings, in particular hollow embossings, in particular located opposite the reduced dewatering zone.
• the reduced dewatering region comprises embossings identical to the embossings of the surface fabric and facing them.
• the first sub-fabric comprises an opening, and a perforated piece of dimensions approximately equal to those of said opening and allowing reduced dewatering relative to said sub-fabric, is fixed under the surface fabric.
• the first sub-fabric comprises a perforated part allowing reduced drainage with respect to said sub-fabric.
• the surface fabric and the sub-fabrics consist of interlaced threads forming meshes.
• the reduced dewatering region has a linear yarn density equal to or greater than the linear yarn density of the surface fabric.
• said reduced dewatering region comprises several zones having different dewatering rates.
• said reduced drainage region comprises a central zone surrounded by at least two edge zones, said central zone and edge zones having different dewatering speeds.
• the central zone has a lower dewatering speed than the dripping speeds of the edge zones.
• the invention also relates to a method of manufacturing a fabric as described above, which is characterized in that it achieves a reduced drainage region using a fragment of fabric or a perforated piece to reduce dripping compared to the first underlay.
• the reduced dewatering region is achieved by using a portion of a web having a higher yarn density than that of the first web, in particular equal to or greater than that of the superficial canvas.
• the reduced drainage region is located in a sub-fabric and is obtained by cutting a fragment of said sub-fabric and then fixing instead a fragment of approximately equal dimensions of a wire density canvas higher than the rest of the underlay.
• said web portion has a linear density in yarn equal to or greater than that of the surface fabric.
• said reduced drainage region is achieved by fixing a portion of a fabric directly under the surface fabric.
• said reduced dewatering region of the sub-fabric is obtained by cutting a fragment of said sub-fabric and fixing instead a perforated part allowing a reduced dewatering with respect to said sub-fabric. sub-web.
• said reduced drainage region is achieved by fixing a perforated part directly under the surface fabric.
• said perforated piece is made of metal or plastic.
• said perforated piece is obtained by depositing a photoresist on the surface fabric and insulating said resin in a perforated mask, the insolated parts of said resin being removed.
• a photoresist on the surface fabric and insulating said resin in a perforated mask, the insolated parts of said resin being removed.
• This is, for example, an organic polymer resin sensitive to ultraviolet rays, the UV radiation causing solubilization of the insolated areas which are then eliminated.
• said perforated piece is obtained by deposition on the surface fabric of a photosensitive resin and insolation of said resin in a perforated mask, the non-insolated portions of said resin being removed.
• the surface fabric is embossed and said piece of fabric or said perforated piece is embossed (e) identically to the embossings of the surface fabric.
• the invention also relates to a security sheet containing at least one fibrous jet obtained by one of the manufacturing methods and / or by means of a web described above.
• the subject of the invention is a sheet comprising at least one watermark and / or at least one security thread, more particularly a security thread appearing in windows, in particular according to the patent application EP 0059056.
• the invention is finally a security document obtained from the security sheet described above.
• the subject of the invention is a means of payment such as a bank note or a check, an identity document such as an identity card or a passport, a ticket, an admission ticket to a ticket cultural or sporting event.
• FIG. 3 represents a sub-fabric of a fabric according to another embodiment of the invention, said sub-fabric -toile being provided with a reduced dewatering zone divided into several different zones of different dewatering speeds
• FIG. 4 represents a portion of a surface fabric provided with an embossing intended to create a shaded watermark in a fibrous jet
• FIG. 5 represents a sectional view of a fibrous jet provided with a watermark manufactured, using the surface fabric of FIG. 4, according to a "conventional" method of the prior art;
• FIG. sectional view of a fibrous jet with a watermark FIG.
• FIG. 7 is a sectional view of a fibrous jet provided with a security thread, manufactured according to a "conventional" method, with the aid of the surface fabric of FIG. 4, according to the method of the invention.
• Figure 8 shows a sectional view of a fibrous jet provided with a security thread, manufactured according to the method of the invention.
• Figure 1 shows a portion of a stack of webs (1) of a forming fabric according to the invention.
• This stack of webs comprises a web surface (2) which is the outermost web of the stack of webs (1), directly in contact with the fiber suspension and on which the fibrous jet (2) is formed.
• Beneath the superficial canvas (2) are two sub-canvases (3,4).
• the second sub-fabric (4) has a linear density in yarns lower than that of the first sub-fabric (3) which itself has a linear density in yarns lower than that of the surface fabric (2).
• Figure 2 shows, in a simplified manner, a sub-fabric (3) of a stack of webs (1) according to the invention, said sub-fabric being provided with a reduced drainage region (5).
• the reduced drainage region (5) has a linear density in yarns greater than that of the remainder of the underlayer (3,4) so that, in this region, during the formation of a fibrous jet, the Dewatering of the fiber suspension is slowed down relative to the remainder of the underlay, and thus the amount of deposited fiber is less than the amount of fiber deposited out of that region.
• FIG. 3 shows, in a simplified way, another embodiment of a stack of webs (1) according to the invention, in which the reduced dewatering region (5) of the sub-fabric (3) is divided into several zones (13, 14) of different dewatering speeds.
• the reduced drainage region (5) comprises a central zone (13) surrounded by two edge zones (14).
• the central zone (13) has a linear density in wires greater than that of the edge zones (14) so that the dewatering speed, and therefore the amount of deposited fibers, in the central zone is less than the dewatering speed. in the edge areas (5).
• Such an arrangement is particularly advantageous when the reduced drainage region is wide.
• FIG. 4 shows a sectional view of a region of the web (2) having an embossing zone (6) for creating a shaded watermark (7) in a fibrous stream (8, 9). More fiber will accumulate in the recessed areas.
• FIG. 5 shows a cross-sectional view of a fibrous jet (8) provided with a watermark (7) produced, using the embossed surface fabric (2) of FIG. 4, according to a "conventional" method of the prior art, on a round shape with a conventional training fabric of a paper machine.
• the fibrous jet (8) thus obtained has ⁇ e excess thicknesses at the location of the watermark (7) corresponding to the hollow embossed areas of the surface fabric (2).
• FIG. 6 shows a sectional view of a fibrous jet (9) provided with a watermark (7) obtained by using the surface fabric (2) of FIG. 4, according to the method of the invention, the first sub-section canvas having a reduced dewatering region to the right of the embossing zone (6).
• the surface of the fibrous jet (9) thus obtained does not have, in contrast to the fibrous jet (8) of FIG. 5, excess thicknesses.
• the watermark (7) is present but is located in a casing made in the sheet thanks to the reduced drainage area, so that although the watermark has reliefs, they do not affect the flatness of the jet (9 ).
• FIG. 7 shows a sectional view of a fibrous jet (10) equipped with a security thread (11) 1.2 mm wide and 25 ⁇ m thick, manufactured on a round shape according to a method " classical “of the prior art.
• the surface of the jet (10) thus obtained has an excess thickness in the safety thread (11), since the amounts of fibers deposited respectively at the level of the safety thread (11) and the remainder of the jet (10) are of the same order of size.
• FIG. 8 shows a sectional view of a fibrous jet (12) provided with the same security thread (11) as that used in FIG. 7, manufactured according to the method of the invention, the first underlap presenting a region reduced dewatering all round the cylinder of the round shape, said region having a width slightly greater than that of the wire, about 1.5 mm.
• the surface of the paper sheet (12) thus obtained does not have an extra thickness due to the security thread (11), the wire (11) being included in the jet at the level of the reduced drainage region.
• the security thread (11) is located in a casing made in the jet (12) thanks to the reduced drainage region, so that the jet (12) is plane.

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• 2006
  • 2006-08-08 FR FR0607238A patent/FR2904834A1/fr not_active Withdrawn
• 2007
  • 2007-08-06 BR BRPI0715119-5A patent/BRPI0715119A2/pt not_active IP Right Cessation
  • 2007-08-06 US US12/373,830 patent/US20090242153A1/en not_active Abandoned
  • 2007-08-06 CA CA 2659729 patent/CA2659729A1/fr not_active Abandoned
  • 2007-08-06 EP EP07858481A patent/EP2052111A1/fr not_active Withdrawn
  • 2007-08-06 WO PCT/FR2007/051784 patent/WO2008050008A1/fr active Application Filing
  • 2007-08-06 RU RU2009107570A patent/RU2439234C2/ru not_active IP Right Cessation

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